The invention relates generally to product-processing apparatus and method for its cleaning, especially apparatus processing products conveyed on conveyor belts with product repositioners.
Product-processing apparatus, such as chillers, steam cookers, and blanchers, are often used to cook or cool food products, such as vegetables, nuts, and shrimp. In continuous shrimp cookers, for example, shrimp are conveyed through a steam-filled chamber on a conveyor belt by a main drive motor. To uniformly cook the shrimp, which may sit on the conveyor belt in a thick layer, it is often necessary to reposition the shrimp one or more times along the belt's carryway path through the cooking chamber. The conveyor belt is guided around an upper, forward roller and a lower, rearward roller in an S-shaped back flip along the conveying path. Shrimp drop off the upper portion of the belt winding around the upper roller and land on the lower portion of the conveyor belt exiting the lower roller. In this way, the shrimp are repositioned on the belt with previously unexposed portions exposed to the cooking steam. Such a repositioning S-flip for a flighted belt is described in U.S. Pat. No. 8,028,618, “Cooler Apparatus and Method,” Oct. 4, 2011, to Robert S. Lapeyre. In the Lapeyre cooker, the upper roller and the lower roller rotate at a greater speed than the belt is driven by the main drive motor. The belt slips on the rollers, and the relative sliding scrapes debris and slime off both the belt and the rollers. But when the belt is lightly loaded, the slip decreases and the belt tends to build up upon exiting the S-flip ahead of the slower moving drive sprockets. The slack in the belt on the carryway necessarily means that the belt is taut and highly tensioned in the return. As the slack continues to build in the carryway, the belt can break in the return.